Corals are the master builders of the animal kingdom. Powered on plankton and their symbiotic algae, hard corals extract the carbon dissolved in seawater and turn it into their calcium carbonate skeletons. Now a company is trying to replicate this process, not to grow reefs, but to create cement.
Cement, though it may seem like a neutral material, is a massive source of carbon emissions. The cement industry is responsible for 5% of global carbon emissions, with each ton of cement producing a ton of CO2. Biomineralization expert Brent Constantz hopes to green the production of cement by capturing flue gases from factories, running them through a saline solution, and using electricity to convert the gases into solids. For 542 million years, corals have been sequestering carbon dissolved in water. Constantz's company Calera may have figured out how to do the same on a much shorter time scale.